Crate vld 

vld — Type-safe runtime validation for Rust

vld is a validation library inspired by Zod that combines schema definition with type-safe parsing.

Quick Start

use vld::prelude::*;

// Define a validated struct
vld::schema! {
    #[derive(Debug)]
    pub struct User {
        pub name: String => vld::string().min(2).max(50),
        pub email: String => vld::string().email(),
        pub age: Option<i64> => vld::number().int().gte(18).optional(),
    }
}

// Parse from JSON string
let user = User::parse(r#"{"name": "Alex", "email": "alex@example.com"}"#).unwrap();
assert_eq!(user.name, "Alex");
assert_eq!(user.age, None);

Modules

collections

combinators

error

format

i18n

Internationalization (i18n) support for validation error messages.

input

modifiers

object

prelude

Common imports for working with vld.

primitives

schema

Macros

impl_default

Generate impl Default for a struct created by schema!.

impl_rules

Attach validation rules to an existing struct.

impl_validate_fields

Generate validate_fields() and parse_lenient() methods for a struct previously defined with schema!.

nested

Create a named nested schema with $ref generation and full JSON Schema.

schema

Define a validated struct with field-level schemas.

schema_validated

Combined macro: generates the struct, parse(), and validate_fields() / parse_lenient() in a single declaration — no need to repeat field schemas.

union

Create a union schema from 2 or more schemas.

Functions

any

Create a schema that accepts any JSON value.

array

Create an array validation schema.

boolean

Create a boolean validation schema.

bytes

Create a bytes validation schema (Vec<u8>).

custom

Create a schema from a custom validation function.

discriminated_union

Create a discriminated union schema.

duration

Create a duration validation schema (std::time::Duration).

enumeration

Create a string enum schema. Validates against a fixed set of values.

intersection

Create an intersection of two schemas (input must satisfy both).

json_value

Create a raw JSON value schema with shape constraints.

lazy

Create a lazy schema for recursive data structures.

literal

Create a literal value schema. Validates exact match.

map

Create a Map schema. Validates [[key, value], ...] arrays into HashMap.

nested

Create a schema for nested/composed structs.

nested_named

number

Create a number validation schema (f64).

object

Create a dynamic object validation schema.

path

Create a path validation schema (std::path::PathBuf).

preprocess

Preprocess the JSON value before passing it to a schema.

record

Create a record (dictionary) schema. All values validated by the given schema.

set

Create a Set schema. Validates arrays into HashSet (unique elements).

socket_addr

Create a socket address schema (std::net::SocketAddr).

string

Create a string validation schema.

union

Create a union of two schemas. Returns Either<A, B>.

union3

Create a union of three schemas. Returns Either3<A, B, C>.